The present invention relates to automatic guns and in particular to guns separately loadable with a projectile and a propellant case.
Conventional automatic guns have used the energy developed by their recoil to automatically eject and reload ammunition. In a known automatic gun, a breech block is removable from a breech position contiguous to a propellant case. After firing, the breech block is removed and an extractor arm is employed to automatically remove and eject the spent propellant case from the bore of the gun barrel. In this known arrangement the recoil motion of the barrel itself is not used to insert the ammunition. In addition, since a combined projectile and propellant case are employed, the internal moving parts must be capable of translating the ammunition a distance equivalent to its entire combined length (The Machine Gun (1955), George M. Chinn, Bureau of Ordnance, Dept. of the Navy, Vol. III, Parts VIII and IX, Pages 265-286 and Pages 351-380; and Vol. IV, Parts X and XI, Chapter 2, Pages 63-125). In another known automatic gun a breech block is mounted on the aft of a movable chamber. This movable chamber is articulated from a common frame which also supports the gun barrel. Being so mounted this movable chamber cannot use the recoil motion of the gun barrel to insert ammunition. Moreover, being arranged to accept ammunition comprising a projectile integrally mounted on a propellant case, the movable chamber must be as long as the combined length of this type of ammunition. Also, since ammunition is inserted into the aft of the movable chamber after its breech block is displaced, a relatively complicated linkage must be provided to simultaneously translate the movable chamber and displace its breech block.
The present invention provides an automatic gun which allows the recoil motion of the barrel to simultaneously open its breech end and ensheath a projectile. Opening the breech end in this manner is accomplished by displacing an aft chamber which is otherwise aligned with the barrel. Opening the barrel also opens the chamber member which can then ensheath a propellant casing during a counter-recoil stroke. When the gun is ultimately returned to its battery position, the barrel has been reloaded with a projectile. The aft chamber has also been reloaded with a propellant case and locked onto the barrel. Such an arrangement therefore provides rapid automatic loading of ammunition. Such loading occurs during recoil and counter-recoil strokes which need only be one-half of the combined length of the projectile and its associated propellant case.